When home based I use 5 gallon glass carboys with syphon locks. When on the road, with turning and starting and stopping and bouncing, my method of using a plastic gallon jug with a screw lid works well. As the fermentation progresses, I release the pressure. When at the max, it may be multiple times a day. I have added sugar. That increases the alcohol content. I prefer working with the natural sugar and getting what I get. When at home, I do use a refractometer, and adjust the sugar. Yes the flavors can be interesting depending on the sugar, but mine is usually made to be dry.